ZOOLOGY: February 2011

Project : Research on Lice

Supervisor: Madam Javeria Farooq

Student: Ahmad Zaib

Roll No: Eight_ 08

Semester: 4^th

Discipline: M.Sc

Department: Zoology

University: Abdul Wali Khan

University Mardan

StudentCell: 0346_9460420

INTRODUCTION TO LICE

Lice (singular: louse) is the common name for over 3000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents. They are obligate ectoparasites of every avian and mammalian order.

Most lice are scavengers, feeding on skin and other debris found on the host's body, but some species feed on sebaceous secretions and blood. Most are found only on specific types of animal, and, in some cases, only to a particular part of the body; some animals are known to host up to fifteen different species, although one to three is typical for mammals, and two to six for birds. For example, in humans, different species of louse inhabit the scalp and pubic hair. Lice generally cannot survive for long if removed from their host. A louse's color varies from pale beige to dark gray; however, if feeding on blood, it may become considerably darker. Female lice are usually more common than the males, and some species are even known to be parthenogenetic. A louse's egg is commonly called a nit. Many lice attach their eggs to their host's hair with specialized saliva; the saliva/hair bond is very difficult to sever without specialized products. Lice inhabiting birds, however, may simply leave their eggs in parts of the body inaccessible to preening, such as the interior of feather shafts. Living lice eggs tend to be pale white. Dead lice eggs are more yellow. Lice are exopterygotes, being born as miniature versions of the adult, known as nymphs. The young moult three times before reaching the final adult form, which they usually reach within a month of hatching.

Lice are optimal model organisms to study the ecology of contagious pathogens since their quantityes, sex-ratios etc. are easier to quantify than those of other pathogens. The ecology of avian lice has been studied more intensively than that of mammal lice. The average number of lice per host tends to be higher in large-bodied bird species than in small ones. Louse individuals exhibit an aggregated distribution across bird individuals, i.e. most lice live on a few bird, while most birds are relatively free of lice. This pattern is more pronounced in territorial than in colonial – more social – bird species.

Bird taxa that are capable to exert stronger antiparasitic defence – such as stronger T cell immune response or larger uropygial glands – harbour more taxa of Amblyceran lice than others.Temporal bottlenecks in host population size may cause a long-lasting reduction of louse taxonomic richness E.g., birds introduced into New Zealand host fewer species of lice there than in Europe. Louse sex ratios are more balanced in more social hosts and more female-biased in less social hosts, presumably due to the stronger isolation among louse subpopulations (living on separate birds) in the latter case.

A few effects of lousiness upon the host;

Lice may reduce host life expectancy. Lice may transmit microbial diseases or helminth parasites. Ischnoceran lice may reduce the thermoregulation effect of the plumage, thus heavily infected birds loss more heat than other ones. Lousiness is a disadvantage in the context of sexual rivalry.

There are two basic types of lice, the sucking lice (Anoplura) and the chewing lice (Mallophaga);

Humans host have three different kinds of lice: head lice, body lice , and pubic lice. Lice infestations can be controlled with lice combs, and medicated shampoos or washes. Adult and nymphal lice can survive on sheep-shearers' moccasins for up to 10 days, but microwaving the footwear for five minutes in a plastic bag will kill the lice.

(H.V.Hoell et al)

1. HUMAN LICE

In general, the life history of human lice is quite similar. Lice have three distinct stages- the egg (nit), the nymph, and the adult. The fertilized female louse lays eggs (up to 200 in head and body lice), which hatch in about a week. The young nymphs go through two molts. Nymphal development takes about 2 to 3 weeks. The third molt produces adult lice. The adult lives 3 to 4 weeks.

Basic differences exist between these lice. The head louse and the body louse are the same species. Authorities however, consider them subspecies due to differences in habits. There is also slight difference in size. Head lice are generally 10-29 percent smaller than body lice. These lice range from 2-3 mm in length, are longer than they are broad, and are dirty-white to greyish black. Head lice generally reside on the scalp or skin and attach the eggs or “nits”) close to the base of the hair.

Body lice generally reside in clothing or bedding. They most frequently occur in seams of undergarments or places where the body is in close contact with clothing, such as the crotch, waistline, or armpits. Their eggs are glued to clothing and only occasionally to body hairs. Body louse contact with the skin is during feeding only.

Crab lice are approximately 1 mm long and about as broad as they are long. They are greyish-white or somewhat pink and crab-like in appearance. They mainly infest the coarse body hairs of the pubic or perianal areas, although they have been taken from the eyebrows also. Their nits are attached to those coarse hairs.

Infestation by head or body lice can come about in a variety of ways. Infestation by crab lice, however, is mostly confined to sexual contact, although they can be acquired from sitting on an “inoculated” toilet seat or from clothing in a crowded locker room.

(Arthur L. Antonelli)

Infestation of lice on the human body (also known as pediculosis) is very common. Cases number in the hundreds of millions worldwide. While lice can occasionally cause significant illness (typhus, relapsing fever and trench fever), a lice infestation is generally more of an itchy and embarrassing experience. Three distinct presentations of lice infection exist -- each is caused by a unique parasite. Head lice (Pediculus humanus capitis) are by far and away the most common infestation and favour no particular socioeconomic group. A genetically close "cousin," Pediculus humanus corporis, is responsible for body lice that are more commonly associated with poverty, overcrowding, and poor hygiene. Pubic lice (“crabs”) are caused by Pthirus pubis and are transmitted by intimate and/or sexual contact.

Lice infestation is a uniquely human experience. Lice do not jump or fly from host to host. They cannot be transited via animals but may be transferred by person to person via direct contact and by fomites (inanimate objects -- for example, caps, combs, sheets, etc).

1.1 Types of Lice

Three different types of lice that infest humans are;

1.1.1: Head Louse

This is a grey-white animal about 2-3 mm in length. The life span of the female louse is about one month. During this time, she will produce between seven to 10 eggs ("nits") per day and attach them firmly to the hair shaft region close to the scalp or body. These nits, which resemble dandruff, are attached with glue like, water-insoluble substance that makes them difficult to remove. After six to 10 days, the nits hatch as nymphs and become adults in 10 days. Head lice are the most common form of lice infestation. The CDC reports that 6-12 million people in the United States are infested each year. Children aged 3-10 years in preschool, elementary school, and day-care centers are most likely to have lice. Girls are more commonly infested, but hair length or personal hygiene is not predictive factors.

Head-lice transmission is most commonly via direct head-to-head contact. Sharing pillows, caps, headphones, and combs/brushes are notorious ways to transmit head lice. Since the head louse dies due to dehydration within two days if not feeding on their human host, contact with carpeting and couches is less commonly seen as a route of transmission. Most lice infestations are asymptomatic (meaning they cause no symptoms). However, itching of the scalp, neck, and behind the ears are characteristic symptoms. Intense scratching may lead to secondary skin infections and associated enlargement of the lymph nodes of the neck and scalp regions. The diagnosis is made by demonstration of the louse or nits. Nits are more easily seen when examined using a Wood's light ("black light") that causes them to fluoresce as pale blue objects attached to the hair shafts near the scalp. A fine-tooth comb run through the hair will also demonstrate adult lice and nits. The body louse is slightly larger than the head louse but has the same general appearance. Unlike the head louse, which lives on its human host, the body louse lives in clothing (commonly in the seamed areas) and then transfers to the human host to feed. The life cycle of the head louse and the body louse .

1.1.2: Body Louse

These are similar in character and duration. An important difference, however, is the ability of the body louse to survive for up to 30 days away from its human host. Body-lice infestation is a prominent public-health problem in communities with large populations dealing with poverty, overcrowding, and poor personal hygiene. Itching is the primary symptom of body-lice infestation. Areas where seams of clothing are tightly adherent to the body are the most likely areas of involvement. Red, itchy bite marks may be seen on the body. The diagnosis of body lice involvement can be made by identifying lice or nits in clothing, bedding, or linens -- especially in the seam regions .

1.1.3: Pubic Louse

The ("crab louse") is distinct morphologically (somewhat rounded with three pairs of legs on either side of the body from which it takes its descriptive name) from the head and body louse. The female lifespan is slightly shorter (three weeks), and she produces fewer eggs per day (three) than her counterparts. The eggs attach to the base of the pubic hair shaft for approximately six to eight days before hatching. In adults, pubic lice are transmitted by direct sexual contact; children generally contact the infection via nonsexual transmission from their parents. Transmission by bed linens and infested clothing is less likely. Intense itching of the pubic area is characteristic. Axillary regions, eyelashes, and even the scalp may be involved. Nighttime symptoms are may be more intense. After being bitten, a bluish colored sore may develop in the involved areas. The diagnosis is established by demonstration of crab-shaped lice attached to the hair shaft. Consideration of infection by other sexually transmitted diseases should be entertained in any adult with pubic lice. Condoms do not prevent pubic-lice infestation. Contrary to popular thinking, pubic lice are not spread by toilet seats .

1.2: BIRD LICE

Bird louse refers to any chewing louse (small, biting insects) of order Phthiraptera which parasitizes warm-blooded animals, especially birds. Bird lice may feed on feathers, skin, or blood. They have no wings, and their biting mouth parts distinguish them from true lice, which suck blood. Earlier all chewing lice were considered to form the paraphyletic order Mallophaga while the sucking lice were thought to consider the order Anoplura.

Almost all domestic birds are hosts for at least one species of bird louse. Chickens and other poultry are attacked by many kinds of bird lice. Bird lice but usually do not cause much harm to a bird unless it is unusually infested as in the case of birds with damaged bills which cannot preen themselves properly. In such cases, their irritation may cause the bird to damage itself by scratching. In extreme cases, the infestation may even interfere with egg production and the fattening of poultry. Unlike true lice, bird lice do not carry infectious diseases. Having coevolved with their specific host, phylogenetic relationships among bird lice are sometimes of use when trying to determine phylogenetic relationships among birds. (Encyclopaedia Britannica. Retrieved 09 April, 2010)

The primary effects of lice on their hosts are the irritations they cause. The birds become;

Restless and do not feed or sleep well. They may injure themselves or damage their

Feathers by pecking or scratching areas irritated by lice. Body weight and egg production may drop. All lice infecting poultry and birds are the chewing type. Mites may be confused with lice, but mites suck blood. In general, each species of lice is confined to a particular kind of poultry, although some may pass from one kind to another when birds are closely associated. Chickens usually are infested with one or more of seven different species; turkeys have three common species. All species of poultry lice have certain common habits. All live continuously on feathered hosts and soon die if removed. The eggs are attached to the feathers. Young lice resemble adults except in color and size. Lice differ in preferred locations on the host, and these preferences have given rise to the common names applied to various species. The incubation period of lice eggs is four to seven days, and development of the lice between hatching and the adult stage requires about twenty-one days. Mating takes place on the fowl, and egg-laying begins two to three days after lice mature. The numbers of eggs probably ranges from fifty to three-hundred per female louse.

The Head Louse is found mainly on the head, although it occurs occasionally on the neck and elsewhere. It usually is located near the skin in the down or at the base of the feathers on the top and back of the head and beneath the beak. In fact, the head of the louse often is found so close to the skin that poultrymen may think it is attached to the skin or is sucking blood. Although it does not suck blood, the head louse is very irritating and ranks first among lice as a pest of young chickens and turkeys. Heavily infested chicks soon become droopy and weak and may die before they are a month old. When the chickens become fairly well feathered, head lice decrease but may increase again when the fowls reach maturity. This louse is oblong, greyish and about 1/10-inch long. The pearly-white eggs are attached singly to the down or at the base of the small feathers on the head. They hatch Within five days into minute, pale, translucent lice resembling adults in shape.

The Body Louse of chickens prefers to stay on the skin rather than on the feathers. It Chooses parts of the body that are not densely feathered, such as the area below the vent. In heavy infestations, it may be found on the breast, under the wings and on other parts of The body, including the head.

When the feathers are parted, straw-colored body lice may be seen running rapidly on the Skin in search of cover. Eggs are deposited in clusters near the base of small feathers, Particularly below the vent, or in young fowls, frequently on the head or throat. Eggs hatch in about a week and lice reach maturity within twenty days. This is the most common louse infesting grown chickens. When present in large numbers, the skin is irritated greatly and scabs may result, especially below the vent.

The Shaft Louse or small body louse is similar in appearance to the body louse, but smaller. It has a habit of resting on the body feather shafts of chickens where it may be seen running rapidly toward the body when feathers are parted suddenly. Sometimes as many as a dozen lice may be seen scurrying down a feather shaft. Since the shaft louse apparently feeds on parts of the feathers, it is found in limited numbers on turkeys, guinea fowl and ducks kept in close association with chickens. It does not infest young birds until they become well feathered.

( Wikipedia.com )

1.2.1: Lice in Pet Birds

There are a large number of species of avian or bird lice, some of
which are named after the bird they parasitize or the area or part
of the body of the birds that they refer to live in it.
Lice are wingless insects and are the most common external
parasites of birds. They are so small they are often invisible
to the naked eye and some time we use a magnified glass.
Lice are placed into two groups: Biting lice and sucking lice.
The entire life cycle of the lice is spent entirely on the bird, and
leaving it (lice) just only to attack other or on another victim.
The eggs are laid in clusters along the shaft of the feathers.
These egg clusters are referred to as nits, and hatch within a
few days, producing nymphs. Nymphs are young immature lice. The
nymphs then go through changes and later become larvae, which go
through several more changes before they finally become mature
adult lice. Adult lice can live for several months on the host,
but they can only live for a few days away from or off their bird
host.
(PetCareTips.net/BirdLice)

Chicken lice live for the most part in the feathers of a chicken and to some degree on the skin. One might suspect that these tiny creatures are blood suckers, and 1.a host of them would eventually do a chicken in. The fact is, chicken lice eat mostly dead skin, scales, and feathers. An individual louse or a small number of lice will do little harm to a chicken, but a large infestation can cause the bird a great deal of grief, perhaps to the point where it will die.

Lice are extremely irritating for our chickens, and a severe infestation can also kill small chicks.Lice are just big enough to be spotted with the naked eye as pale insects on the skin. When you examine your chicken’s feathers, you might spot them crawling around the base of the feathers, and you may see clusters of their eggs on the feather stems. Lice love somewhere soft and warm, so also check under the wings and around the vent area. Other symptoms include a dirty vent area, weight loss and reduced egg yield.There are several types of biting lice that effect chickens and other poultry. These are known as ectoparasites or external parasites as they live on the outside of the bird. They range in size from about 1 to 4mm and can be found crawling on the bird at the base of the feathers, spreading from bird to bird by direct contact. Off the bird lice can survive for a few days so although less likely, can also spread from bird to bird via the hen house or litter. Most chickens will have a few lice on them from time to time but it's important not to let the numbers get out of control.

(Poultry Farm.com)

1.2.2: Pigeon Lice

The slender pigeon louse is a long, slender louse with two bladelike hairs near the front of its head. The threadlike antennae are five-segmented. They measure 0.078 to 0.12 inches in length. This louse is only found on four species of pigeons, including the widely distributed rock dove or city pigeon. Rock doves (and their ectoparasites) live with humans and have been introduced throughout the world. The distribution of the slender pigeon louse is thought to match that of the rock dove. They are found only among the feathers on the upper and lower sides of the wings of pigeons. Slender pigeon lice eat the fluffy parts of the feathers. The slender body of this louse allows it to move in between the feather barbs. They grab the edges of feather barbs with their jaws to avoid the preening activities of the host.Females attach their eggs on the underside of the wing feathers near the pigeon's body. They hatch in three to five days at 98.6°F. They are used as research animals by scientists studying how animals change over time and how they interact with parasites.

(Kim, K. C., H. D. Pratt, and C. J. Stojanovich)

1.3: OBJECTIVES

To study behaviour of Anoplura and Mallophaga lice .
To compare Anoplura with Mallophaga lice .
To observe the effect of Anoplura and Mallophaga on host body .
To study the protective measurements against lice .

2. REVIEW OF LITERATURE

2.1: JANE E. BRODY (September 21, 2010) Reported that Besides a sometimes itchy scalp from an allergic reaction to their saliva, scientists say, lice cause no physical distress and transmit no diseases.

2.2: SINDYA N. BHANOO (September 7, 2010) Reported that Researchers have found that light-colored lice live on light-colored birds, whereas dark-colored lice live on dark-colored birds.

2.3: Koch T, et al (2001 May;10) Reported that Head lice infestation is a public health issue. In the effort to compile an evidence-base about the physiology, detection, treatment, effects and management strategies of head lice infestations we reviewed current literature. This literature signalled significant evidence gaps and these gaps provide incentives for further research.

2.4: Robert H Vander Stichele, et al (14 July 1995 ) Reported that Total of 28 trials were identified and evaluated according to eight general and 18 lice specific criteria. Of the 14 trials rated as having low to moderate risk of bias, seven were selected as they used the main outcome measure. These seven trials described 21 evaluations of eight different compounds and placebo (all but two evaluations were of single applications). Only permethrin 1% creme rinse showed efficacy in more than two studies with the lower 95% confidence limit of cure rate above 90%.

2.5: CL Bartels, et al Reported that Current research suggests that head lice resistance exists, but little is known regarding the actual incidence of this resistance or whether this incidence is increasing. More research is needed to assess the status of this problem. Proposed mechanisms for head lice resistance include knock-down resistance, glutathione S-transferase-based resistance, and monooxygenase-based resistance.

2.6: O. Eng. leis, cf. et al Reported that The term lice is applied to small wingless insects, parasitic upon birds and mammals, and belonging strictly speaking to the order Anoplura, often included among the Hemiptera, though the term is frequently extended to the bird-lice constituting the sub-order Mallophaga, formerly included among the Neuroptera . Both agree in having nothing that can be termed a metamorphosis; they are active from the time of their exit from the egg to their death, gradually increasing in size, and undergoing several moults or changes of skin .

2.7: Heather Brannon, (Updated April 09, 2008) Reported that The adult louse feeds about 5 times a day by piercing the skin with its claws, injecting irritating saliva, and sucking blood. Lice do not become engorged like ticks, but their color changes to a rust color after feeding. Head lice hold onto the hair with hook-like claws found at the end of each of their 6 legs. Adult lice are active and can travel quickly.

2.8: Hipolito RB et al (01MAR-2001) Reported that This study found that 'a combination of 1% PER {Nix} and TMP/SMX {Bactrim} is an effective alternative therapy for HLI. We recommend that the dual therapy with 1 %PER and oral TMP/SMX be used and reserved in cases of multiple treatment failures or suspected cases of lice-related resistance to therapy.

2.9: The study published in the November 2006 by Dale Clayton and Reprted that "Each year, millions of children are infested with head lice, a condition known as pediculosis, which is responsible for tens of millions of lost school days," the study's author write. "Head lice have evolved resistance to many of the currently used pediculicides [insecticide shampoos]. ... Hot air is an effective, safe treatment and one to which lice are unlikely to evolve resistance”.

2.10: Karen MacKenzie ( Revised September 2005 ) Reported that Pediculosis humanus captis, or head lice infestation affects most children at some time during their school days. Unfortunately, doctors and pharmacists still advise parents to treat lice with neurotoxic poisons that can be readily absorbed through the skin. This Research Report is set up in two sections. In the first section, you'll find credible articles which suggest that tea tree oil and solutions thereof may be successfully used to treat lice infestations.In the second section you'll find several credible articles which suggest that you may want to think twice before using the popular chemical treatments on your children.

2.11: Admin (August 21st, 2009 ) Reported that There are many substances used to suffocate head lice, and all are readily available household goods. This explains part of the popularity of the method as it does not need the use of dangerous insecticides and chemicals, and is entirely safe – unless you happen to be a head louse! While the process itself makes sense the substances used sound rather bizarre: mayonnaise, Vaseline and olive oil are frequently cited as the best at smothering head lice, and the choice is yours as to which to use first.

2.12: Tina Koch et al ( 21 DEC 2001) Reported that Head lice infestation is a public health issue. In the effort to compile an evidence-base about the physiology, detection, treatment, effects and management strategies of head lice infestations we reviewed current literature. Our conclusions from the literature are that parents of children are responsible for head lice detection and treatment but have varying access to advice about how best to treat this condition. Head lice are a low priority for health professionals in Australia, whereas parents and teachers believe the problem necessitates greater attention. It is important to provide a unified evidence-based approach to good information.

2.13: Jones KN, Reported that Head Lice (Pediculus humanus capitis) are a common parasite found in human hair. School-age children from age 3-10 are often the most effected by outbreaks of lice infestations because of their sustained proximity and propensity for sharing hats, combs and clothing. Non-prescription sales of head lice products and related school expenditures in the United States alone cost consumers an estimated $350 million yearly. The two most successful conventional pyrethrum-based pediculicides are Ridand Nix averaging sales of more than $10 million each annually.

2.14: James F. Dill, Clay A. Kirby,. Reported that The head louse (Pediculus humanus capitis) is gray in color but tends to take on the hair color of the host. This insect pest is usually found on the lower back of the head and behind the ears. The female is about 1/16″ to 1/8″ long and flattened in shape; the male is a bit smaller. Hook-like claws are at the end of each of six legs to help anchor the louse to the hair shaft. Head lice do not jump or fly.

2.15: The lead researcher,Dr. Martin Krkosek Reports that More than 500 news stories have reported the findings. In the wake of extensive negative press about sea lice from salmon farms, a "war on fish farmers" was declared in British Columbia and 20,000 people have signed Alexandra Morton's petition to close salmon farms.

2.16: EIbarra,J et al.,( Retrieved November 2, 2 9 ) Reported that Since the medication treatment wasnot repeated, this might have affected results but in either case, combing was effective.

2.17: Top of Form Miwa Takano-Lee et al Reported that We examined the potential value of six purportedly effective “home remedies” (vinegar, isopropyl alcohol, olive oil, mayonnaise, melted butter, and petroleum jelly) to treat head louse infestations and the likelihood of drowning lice by water submersion.

2.18: J. A. Hunter and S. C. Barker Reported that All five groups of head lice were less susceptible to malathion, pyrethrums and permethrin than were lice from the reference strain. Moreover, the degree of susceptibility to these insecticides varied substantially among schools. Thus, a pediculicide that controlled lice at one school in Brisbane would not necessarily control head lice at another school in the same city. These preliminary data indicate that detailed information on the susceptibility of the different populations of head lice in Queensland to the different insecticides available is needed to maximize the chance of effective control of these increasingly common parasites.

2.19: According to Encyclopedia Brittinica Human louse (Pediculus humanus), also called body louse, a common species of sucking louse in the family Pediculidae (suborder Anoplura, order Phthiraptera; that is found wherever human beings live, feeds on blood, and can be an important carrier of epidemic typhus and other louse-borne human diseases such as trench fever and relapsing fever.

2.20: Ewen F. Kirkness et al (Contributed by May R. Berenbaum, April 14, 2010 ) Reported that As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects.

2.21: E. F. Kirkness, et al Reported that The human body louse seems to appear out of nowhere during economic downturns, wars and other crises that cause people to live in unsanitary conditions. It is closely related to the head louse, Pediculus humanus capitis, which also feeds on human blood. But the body louse lives in clothing and, unlike the head louse, can spread bacterial diseases.

2.22: Williams LK - Pediatrics ( 01-MAY-2001) Repoted and Found that 'Most children with nits alone did not become infested. Policies requiring exclusion from school and treatment for all children with nits alone are likely excessive. Instead, these children may benefit from repeated examination to exclude the presence of crawling lice.' This was a good study because if found that only 18% of kids with nits actually developed an active lice infestation. So just because you have nits, either before or after treatment, doesn't mean that your child is still infested with lice.

2.23: William E. Ferguson in (Brittinica Concise Encyclopedia) Reported that Any of three types of sucking louse that infest humans. The body louse (mainly Pediculus humanus humanus, also called human louse or cootie) and head louse (P. h. capitis) are spread by person-to-person contact and through shared clothing, bedding, combs, and other personal items. Body lice carry the organisms that cause relapsing fever, trench fever, and typhus. Head lice may cause impetigo. Both are readily spread under conditions of overcrowding, especially among children. The crab louse, or pubic louse (Phthirus pubis) infests primarily the pubic region and occasionally other hairy regions. Its first pair of legs is smaller than the other two pairs, making it look like a crab. Crab lice are transmitted primarily through sexual intercourse. Lice infestations can be quickly cured with shampoos, soaps, and lotions containing benzene hexachloride, along with the thorough washing of bedding and clothing.

2.24: Adam O Goldstein, MPH Beth G Goldstein., Reported that Pubic lice (crabs) are most often spread from one person to another through sexual contact. Pubic lice can be found in all parts of the world, affecting men and women of all races. And that Head lice are usually spread from one person to another through casual contact. Although head lice can be unpleasant, there are effective treatment options available. It is important to find and treat lice quickly to avoid spreading them to others.

2.25: CL Bartels, et al Reported that Head lice infestation is a common, worldwide problem. The widespread use of insecticide treatments together with inadequate treatment methods has led to a concern regarding the potential development of resistant head lice. This literature review examines the reports of resistance of the head louse as well as the purported mechanisms involved.

2.26: Robert H Vander Stichele, et al (14 July 1995) Reported that Head lice are among the most common of human ectoparasites, though they are not vectors of serious diseases and in many cases do not cause symptoms. Treatment with natural pyrethrines has been known for more than 100 years, and lindane has been used since the second world war. The synthetic pyrethrines were marketed in the 1950s, malathion and carbaryl in the ‘60s, and permethrin in the ‘80s. Although products abound, the prevalence of head lice remains high and epidemics occur regularly despite all efforts at control. Problems such as fear of insects (entomophobia), fear of stigmatisation, and denial of infection by patients and schools may cause under-treatment, overtreatment, and unnecessary prophylaxis, which can lead to development of resistance and insufficient control of epidemics. Furthermore, many of the commercially available treatments might be underdosed, incorrectly labelled, or ineffective.

2.27: Bartels CL, et al Reported that Head lice infestation is a common, worldwide problem. The widespread use of insecticide treatments together with inadequate treatment methods has led to a concern regarding the potential development of resistant head lice. This literature review examines the reports of resistance of the head louse as well as the purported mechanisms involved.

2.28: A recent study done by Harvard University did show that Some, but not All (or even most) head lice are resistant to common prescription and over-the-counter medications (OTC). There is no information on how widespread resistance may be in the United States. Resistance (medication not working) is more likely in people who have been treated many times for head lice.

2.29: Dr. P. Banerji of India Reported that Lice are just small insects crawling over the head and playing hide and seek on every hair strand. There are lots of effects parents should consider regarding their children having lice. One of the effects is that, they might be afraid to mingle with others especially if their play mates know that they have lice. It would affect to their self confidence. One more thing, in school they might be criticize by their classmates or school mates. Since mingling with people with head lice is one of the possibility that you can have it too. It is really important for parents to take the precautionary measures. Moreover, head lice can also affect to their learning, because instead of studying or focusing to the class discussion they are busy scratching their heads.

2.30: Dennis P. West, (September 1, 2004) Reported that In a study of head lice diagnosis and management accuracy, samples of material that were considered by healthcare professionals and the public to verify evidence of lice or nits were shown to contain a large proportion of materials that were not indicative of infestation.⁶ Only 53% of materials submitted as proof of infestation contained lice or nits, suggesting that about half of all diagnoses by this group were potentially inaccurate. Notably, among children attending schools with no-nit policies, 73% were identified as having lice infestation, but only 39% of the samples from these children contained material that supported a diagnosis of head lice. A comparison of results from schools with and without no-nit policies found that children who were lice-free were erroneously excluded from class more frequently than children with active infestations. These poor results confirm the need for a managed approach to care that promotes accurate diagnosis and appropriate treatmen.

2.31: Joshua Duvauchelle, Reported that The bird louse or bird mite is the colloquial name given to the Macronyssidae mite, a parasite that lives on birds. The insect consumes the bird's blood, feathers and skin. If found in your home, bird lice may bite you and cause itching and skin irritation. Take steps to kill bird lice and prevent bird lice infestations to protect your home from these biting pests.

2.32: Dale H. Clayton and Sarah E. Bush, Reported that Louse-infested bird feathers on an electric fan and flew pigeons and doves like kites on strings in a study that found small lice stick to small birds and big lice prefer big birds. This study also showed why size matters to parasites: Lice infest bird species with feathers that are just the right size so the insects can hide between individual “barbs” – the hair-like branches that extend from the shaft of each feather. When lice can hide in the feathers, the birds cannot preen them off with their beaks.

2.33: Kirchofer et al (November 1, 2001) Reported that E ach year approximately 6 to 12 million Americans are infested with head lice, and the incidence rates of those affected continue to rise. Most of those infested with head lice are school children between ages 5 to 12. At present, no compulsory national reporting system exists for head lice, but outbreaks among elementary school students are frequently reported. According to Surveillance Data Inc., nearly 80% of school districts had at least one lice outbreak in 1997. An estimated 6 million elementary students, one in four, were infested in 1997.

2.34: Arun Kumar Saxena et al in (November 1, 2006) Reported that The rate of population expansion of an ischnoceran Phthiraptera, Goniocotes gallinae (infesting the domestic fowl, Gallus gallus domesticus), on the basis of in vitro and in vivo studies. Data obtained from in vitro rearing were utilized to construct the life history of the louse. The values of the gross reproductive rate (12.49 female eggs/female), net reproductive rate (8.31 female eggs/female), mean length of generation (36.91 days), precise generation time (35.65 days), finite rate of increase (1.06 female/days), and intrinsic rate of natural increase (0.059) of G. gallinae were determined. However, doubling-time values recorded during in vivo studies (14 days) was comparatively higher than those during in vitro rearing (11.73 days).

2.35: Encyclopaedia Britannica (Retrieved 09 April 2010) Reported that Bird louse refers to any chewing louse (small, biting insects) of order Phthiraptera which parasitizes warm-blooded animals, especially birds. Bird lice may feed on feathers, skin, or blood. They have no wings, and their biting mouth parts distinguish them from true lice, which suck blood. Earlier all chewing lice were considered to form the paraphyletic order Mallophaga while the sucking lice were thought to consider the order Anoplura. Recent reclassification (Clay, 1970) has combined these orders into the order Phthiraptera. The bird lice belong to two suborders, Amblycera and Ischnocera, although some members of these suborders do not parasitize birds and are therefore not bird lice.

2.36: Vincent Iannelli , (Updated October 20, 2010) Recommends that 'Permethrin 1% (Nix) is currently the recommended treatment for head lice, with retreatment in 7 to 10 days if live lice are seen' and that 'treatment failure does not equate with resistance, and most instances of such failure represent misdiagnosis/misidentification or noncompliance with the treatment regimen.

2.37: Los Angeles, CA, (March 24, 2009) Released in the March issue of Archives of Dermatology, researchers in Germany concluded that Wet combing is more accurate than a visual inspection for discovering an active case of head lice. Hair Fairies, The Head Lice Helpers, began using this method in 1999 as part of their Nit-Zapping process that performed in their salons nationwide.2.38: Deborah Altschuler, L. Lance Sholdt, Reorted that I believe that the head louse, Pediculus capitis, is a potential vector of louse-borne diseases. My opinion is based on a review of the submitted papers from the National Pediculosis Association, my own field experience with human lice in Ethiopia and Peru and discussions on the subject with Professor James R. Busvine of the London School. It has yet to be proven that head lice do not transmit disease. There is, however, laboratory evidence that they are susceptible to infection with Rickettsia prowazeki and subsequently become infectious. It is time now, therefore, to ensure that cautionary statements are included regarding head lice whenever human lice and louse-borne diseases are discussed.

2.39: Nicolle (1920) claimed that Head lice could transmit typhus. Mackenzie (1942) believed that body lice were evolutionary forms of the head louse and that both were vectors of typhus. Gerberg suggested in 1973 that there is a potential hazard for disease transmission by head lice in urban areas. Maunder (1983) wrote that while all three species of human lice were potential vectors, the body louse was most important because it is found in large numbers and their feces are more likely to be trapped in the clothing. Weidhaas and Gratz noted in a 1982 WHO publication that head lice may act as vectors but are not responsible for louse-borne disease outbreaks in the absence of body louse infestations.

2.40: Foster stated that Head lice may have been responsible for an outbreak of typhus in the Philippines in 1915. Two years later, Haight, suggested that a typhus case in Toronto, Canada could have been transmitted by a head louse.

2.41: Gaon (1973) Reported that Both head and body lice were found in large numbers in louse-borne disease epidemics. He noted that there was never a case when only head lice were observed, even though 5-10% of the population might have been infested. However, he stressed that, as body lice disappear, considerable importance must be attached to head lice as vectors of disease.

ZOOLOGY

Saturday, February 26, 2011

Unique Behaviours Of Elephants

Saturday, February 12, 2011

MY THESIS [ 1st and 2nd CHAPTERS ]